The role of NAD-linked glycerol-3-P dehydrogenase in glyceride biosynthesis is open to question by virtue of its coenzyme specificity and the discovery of the acyl dihydroxyacetone-p pathway. We wish to assess the role of glycerol-3-P dehydrogenase in glyceride metabolism by: a) characterizing and comparing glycerol-3-P dehydrogenase isozymes purified from avian tissues having primarily lipolytic or lipogenic activities, b) correlating the activity of glycerol-3-P dehydrogenase with that of the enzymes of the acyl dihydroxyacetone -P pathway in lipolytic and lipogenic tissues, and c) observing changes, if any, in the chicken liver glycerol-3-P dehydrogenase isozymes and the acyl dihydroxyacetone-P pathway enzymes during starvation.